Chevrolet 1999 Monte Carlo Owner's Manual page 121

Oil Warning Light
This indicates that oil is not going through your engine
quickly enough to keep it lubricated. The engine could
be low on oil or could have some other oil problem.
Have it fixed right away.
The oil light could also come on in two other situations:
D
When the ignition is on but the engine is not running,
the light will come on as a test to show you it is
working, but the light will go out when you turn the
ignition to START. If it doesn't come on with the
ignition on, you may have a problem with the fuse or
bulb. Have it fixed right away.
D
If you make a hard stop, the light may come on for a
moment. This is normal.
If you have a problem with
your oil, this light may stay
on after you start your
engine, or come on when
you are driving.
CAUTION:
Don't keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches fire. You or others could be burned.
Check your oil as soon as possible and have your
vehicle serviced.
NOTICE:
Damage to your engine from neglected oil
problems can be costly and is not covered by
your warranty.
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